The present invention generally relates to optical fiber connector assemblies. More particularly, the invention relates to an optical fiber connection arrangement that improves reliability and optical performance while reducing maintenance and manufacturing costs.
The speed and bandwidth of data transmission over fiber optic cable render optical fiber communication particularly advantageous for certain applications. Fiber optic connector assemblies typically include mating ferrules and housings, which hold the fiber in a rigid or semi-rigid mounting within a fiber passage. The core of the optical fiber carries the optically encoded information, and one section of the fiber optic core held in one ferrule and another section of the fiber core is held in another ferrule. Perfect concentricity of the mating fiber cores permits maximum light transmission over the interconnection while misalignment of the mating fiber cores either increases insertion loss or disrupts transmission altogether.
Expanded-beam optical coupling is one approach to coupling one optical fiber to another. Expanded-beam coupling uses a set of self-focusing lenses to focus the optical beam between two connecting fibers. The opposing fiber optic cables are each terminated with one self-focusing lens and are rigidly mounted within the ferrules, each lens being adjacent to the mating surface of the ferrule. Once the ferrules are physically mated, the lens/lens combination provides the optical coupling between the fiber cables. This approach has the disadvantage of necessitating a rigid interlocking arrangement between the ferrule housings in order to ensure fiber core concentricity.
In another approach, a butt-coupled connection abuts one fiber core to the other fiber within the ferrules are coupled by. In this approach, one ferrule has a protruding fiber core, or xe2x80x9cpigtailxe2x80x9d, that moves within the ferrule to accommodate the mating and unmating of the ferrules. A spring is included behind the pigtail to exert a force on the fiber in order to maintain the butt coupling between the fibers during environmental shock and vibration. Unfortunately, the pigtail with the spring-enabled movement complicates module design and manufacturing assembly.
There is a need for a robust fiber optic connector arrangement that maintains fiber core alignment and simplifies optical coupling between two fiber cables. An arrangement and a system that addresses the aforementioned problems, as well as other related problems, are therefore desirable.
In various embodiments, the invention provides an optical fiber connector arrangement that includes a first ferrule having an expanded-beam coupling arrangement disposed therein. The expanded-beam arrangement within the first ferrule includes a first lens that is coupled to a first optical fiber and a second lens that is coupled to a second optical fiber, wherein the second optical fiber protrudes from the first ferrule. The connector arrangement further includes a second ferrule arranged to receive the first ferrule. The second ferrule supports a third optical fiber and is shaped to receive a portion of the first ferrule. The second optical fiber is butt-coupled to the third optical fiber within the second ferrule when the second ferrule is engaged with the first ferrule.
It will be appreciated that various other embodiments are set forth in the Detailed Description and Claims that follow.